Electronic musical instrument with expression control device for simultaneously controlling different tone signals by different amounts

ABSTRACT

An electronic musical instrument includes two different music part playing sections such as an organ section and a rhythm section. The tone signal from the organ section is applied to an amplifier followed by a loudspeaker through a variable resistor for expression control, while the tone signal from the rhythm section is applied to the amplifier through a resistor having a resistance higher than the minimum resistance of the variable resistor and lower than the maximum resistance of the same. The input sides of both resistors are shunted by another resistor having a resistance comparable with the output impedance of the playing sections. When the variable resistor is operated, the rhythm section signal is subjected to volume control of a narrower range than the organ section signal.

O Umted States Patent 1151 3,672,253 Hiyama [4 1 June 27, 1972 [s41 ELECTRONIC MUSICAL INSTRUMENT 3,255,296 6/1966 Peterson... ..84/1.24 WITH EXPRESSION CONTROL DEVICE 3,316,341 4/1967 Peterson... ...84/ 1.24 3,591,700 7/1971 Neubauer.... ..84/1.24 SLY 2,230,836 2/1941 Hammond 84/ 1.24 X C0 0 N D FERENT TONE 3,045,522 7/1962 Markowitz et al.. ..84/1.27 SIGNALS BY DIFFERENT AMOUNTS 3,078,753 2/1963 Gibbs et a1 ...84/1.27 3,193,609 7/1965 Meyer ..84/1.27 [72] namamasu' Japan 3,374,316 3/1968 Slaats et al ..s4/1.27 x [73] Assignee: Nippon Gakki Seizo Kabushiki Kaisha,

Shizuokzkken, j an Primary Examiner-Lewis H. Myers Assistant ExaminerStanley J. Witkowski [22] F11ed: March 15, 1971 A0,ney p]ynn & Frishauf 21 A LN 124027 1 57 ABSTRACT [30] Foreign Application Priority Data An electronic musical instrument includes two different music part playing sections such as an organ section and a rhythm March 16, 1970 Japan ..45/24807 section. The tone signal from the organ section is applied to an amplifier followed by a loudspeaker through a variable re- [52] U.S.Cl ..84/1.27, 84/1.17,84/1.22, s stor for expression control, while the tone signal from the 34/114 rhythm section is applied to the amplifier through a resistor 511 1m. (:1. ..Gl0h 1/02 having a resistance higher than the minimum resistance of the [58] Field of Search ..s4 1.01,1.03,1.09,1.1, 1.17, variable resistor and lower than the maximum resistance of 84l118 1'22 2 L27 DIG 22 the same. The input sides of both resistors are shunted by another resistor having a resistance comparable with the out- [56] References Cited put impedance of the playing sections. When the variable resistor is operated, the rhythm section signal is subjected to UNITED STATES PATENTS volume control of a narrower range than the organ section si nal. 2,142,580 l/1939 Williams ..84/l.27 X g 2,585,357 2/1952 Wayne ..'..84/1.17 5 Claims, 4 Drawing Figures 1 ORGAN SECTION EXPRES SlON CONTROL NETWORK r= R4 .r i TONE KEYBOARD Igfig i w A g m MP 1 GENERATORS SECTION 3 44 51 A I 1 1o 11 I RHYTHM SECT ON. V. W I i I PERCUSSION TONE R5 I 3 I souno KEYER COLORING i l f in OENERATOR '6 q FILTER 4 B ELECTRONIC MUSICAL INSTRUMENT WITH EXPRESSION CONTROL DEVICE FOR SIMULTANEOUSLY CONTROLLING DIFFERENT TONE SIGNALS BY DIFFERENT AMOUNTS BACKGROUND OF THE INVENTION This invention relates to an electronic musical instrument and more particularly to an expression control network thereof for controlling in different ranges the tone signals from different music part playing sections, such as an organ section and a rhythm section.

With an electronic musical instrument, such as an electronic organ, there is customarily incorporated a rhythm sound playing section, some manual and some automatic, as well as a normal musical scale tone playing section (organ section).

A normal electronic organ is provided with an expression pedal to control the volume of audible sounds to be produced.

Accordingly, it is desired to control by the expression pedal the volume of percussion (e.g. cymbals, maracas, claves, and drums) sounds produced by the rhythm section incorporated into the organ as well as that of organ sounds. It is, however, not desired to control the percussion sounds by the common organ expression pedal with the same characteristics as the organ sounds produced by the organ. The reason will be easily appreciated by taking into consideration a practical performance with a natural melody instrument and a natural rhythm (percussion) instrument.

The volume variation range of a normal rhythm instrument such as a drum is relatively narrow as compared with that of a melody instrument. The rhythm instrument maintains, therefore, a certain sound intensity even when the sound of the melody instrument is low. In view of the foregoing, accordingly, it has been contemplated to control the rhythm sounds produced by the rhythm section and the melody sounds produced by the organ section in an independent manner with separate control means. However, such separate control means give rise to complexities in construction and operation.

It is, accordingly, an object of this invention to provide an electronic musical instrument such as an electronic organ having a novel expression control network which permits volume controls of different ranges for signals from different music part playing sections, respectively.

Another object of this invention is to provide an electronic musical instrument having an organ section and a rhythm section, in which instrument the rhythm section sounds are con trolled in volume within a narrower range than the organ sounds by means of the common expression pedal.

SUMMARY OF THE INVENTION According to this invention there is provided an electronic musical instrument comprising two different music part playing sections (e.g. an organ section and a rhythm section), a novel expression control network for receiving tone signals from the both playing sections and controlling the volumes thereof, an amplifier for amplifying signals from the expression network and a loudspeaker for converting signals from the amplifier into audible sounds; wherein the expression network includes a first input terminal for receiving a tone signal derived from one of the playing sections, a second input terminal for receiving a tone signal derived from the other of the playing sections, an output terminal for delivering a tone signal to the amplifier, a first resistor connected between the first input terminal and the output terminal and having a resistance variable for expression control by a manual operation, a second resistor connected between the second input terminal and the output terminal and having a resistance fairly higher than the minimum resistance of the first resistor and fairly lower than the maximum resistance of the same, and a third resistor connected between the first and second input terminals and having a resistance comparable with the output impedance of the playing sections.

, BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 shows a block diagram embodying an electronic musical instrument according to this invention;

FIGS. 2A and 2B are two equivalent circuits in two electrical conditions of the expression control network shown in FIG. 1;

FIG. 3 shows a control characteristics diagram obtained with the expression control network of the present invention; and

FIG. 4 illustrates an expression pedal arrangement according to the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring to FIG. 1, the invention is explained with reference to an embodiment of an electronic musical instrument which includes an organ section and a rhythm section as two different music part playing sections. In the organ section 1, as is well known, outputs from tone generators 2 are coupled to a keyboard section 3, and outputs from the keyboard section 3 are coupled to tone coloring filters 4. With a conventionally designed electronic organ, in practice, the keyboard section 3 generally includes an upper keyboard for melody perfonnance, a lower keyboard for chord performance, and a pedal keyboard for bass performance. The tone signals are selectively derived from the tone generators 2 upon operation of the respective keyboards, and the derived tone signals are fed into the respective tone coloring filters to obtain musical tone signals having proper timbers.

The reference numeral 5 denotes a rhythm section, which may be of a manual play type or may be of an automatic play type. One example of the rhythm section 5, as shown, may include generators 6 for producing percussion sounds such as drums, tom-toms, wood blocks and cymbals and outputs of the generators 6 are coupled to keyers 7 and in turn to tone coloring filters 8. The keyers 7 may include, for example, keyboard operated switches or switching circuits for the manual play type, or pulse triggered switching circuits associated with a rhythm pattern pulse generator and rhythm selector switches for the automatic play type.

Output signals of the organ section 1 and the rhythm section 5 are hereinafter referred to as organ signal and rhythm signal" respectively.

In accordance with the present invention, there is provided a novel expression control network 9 to control the levels of the organ and rhythm signals. The network includes first, second and third resistors R,, R and R; as shown. The output of the organ section 1 is coupled to a first input terminal A via a resistor R and in turn to an output terminal 0 through the first resistor R, such as CdS device whose resistance varies in accordance with amount of light irradiated thereto. The output of the rhythm section 5 is coupled to a second input terminal B via a resistor R and in turn coupled to the output terminal 0 through the resistor R whose resistance is fairly large as compared with the minimum value of the variable resistor R and is fairly small as compared with the maximum value thereof. The output terminal 0 is connected to an amplifier 10 and in turn to a loudspeaker.

A typical value for the resistor R is around 200 R9 in the case that the resistor R varies over a typical range of 10 R0. to 1 mi). The resistors R and R may be the inherent output impedances of the respective sections 1 and 5, typical values for the resistance R, and R, being together around 10 k0. Otherwise, separate additional resistors should be provided if each section includes a last stage, such as an emitter follower, having too low an output impedance.

The input terminals A and B are interconnected by the resistor R whose value is comparable with the output impedance R and R and is desirable to be fairly small as compared with the resistor R a typical value therefor being around 10 k0.

The amplifier 10 has an input impedance, or a load for the network 9. The amplifier input impedance is represented by a resistor R in the drawing, a typical value therefor being around I00 k9.

The variable resistor R above-mentioned is preferably a light sensitive resistor irradiated by a light source 12 connected across a suitable power source (not shown), and the amount of light applied to the resistor R is controlled by a shutter 13 disposed between the resistor R and the light source 12 and arranged to move with an expression pedal. As shown in FIG. 4, the shutter 13 is perforated with an opening 14 in the fonn of an arcuate triangle. The width of the opening 14 increases gradually from one end to another end. When the expression pedal is not operated by the foot, the light beam to be applied to the resistor R, is restricted or blocked by the minimum width of the opening 14 of the shutter 13 and in consequence the value of the resistor R, becomes maximum (1 MO). When the expression pedal is completely depressed by the foot the maximum light amount is applied to the resistor R by virtue of the maximum width of the opening 14, and in consequence the value of the resistor R becomes minimum 10 k9).

As described above, the resistor R has the maximum value 1 M when the expression pedal is not operated. The value is sufiiciently large as compared with those of the resistors R and R connected in series across the resistor R,. In this case, accordingly, the equivalent circuit of the expression control network 9 will be as shown in FIG. 2A. On the other hand, the resistor R, has the minimum value 10 k0 when the expression pedal is completely depressed. In this case, contrary to the foregoing, the resistor R can be neglected with respect to the resistor R Accordingly, the equivalent circuit of the expression control network 9 will be as shown in FIG. 2B.

In FIGS. 2A and 2B, the organ section 1 and the rhythm section are respectively shown by sources c and 2,; each having zero internal impedance.

As shown in FIG. 2A, organ and rhythm signals c and e are together fed into the amplifier through the resistor R when the resistor R has the maximum value (1 MG). In this case, however, the signal e will be divided by means of the resistor R l0 K0) and the resistor R (10 kit), and the signal level for the e signal at point B will be one half the signal level at point A. Namely, assuming that the signal e has the same level as the signal e the level of the signal 2 is smaller than that of the signal e,, by about 6 dB at point B.

As shown in FIG. 2B, the signals c and e are together fed into the amplifier 10 through the resistor R when it has the minimum value (10 k0). In this case, contrary to the foregoing, the signal e will be divided into half at point A by means of the resistor R (10 k9) and the resistor R (10 kfl), and the signal level for the e signal at point A will be one half the signal level at point B. It will be appreciated, under such conditions as above-mentioned, that the level of signal 2,, is smaller than that of signal e by about 6 dB at point A.

FIG. 3 shows a control characteristic diagram of the levels of signals e and e,, as a function of the value of resistor R, which varies continuously from the maximum value to the minimum value in accordance with operation of the expression pedal. In the drawing, the broken line C shows the control characteristic with respect to the signal 2,, and the full line D with respect to the signal e As can be seen from FIG. 3 and the foregoing description, the volume of rhythm sounds based on the signal e is larger than that of organ sounds based on signal e by about 6 dB when the expression pedal is not operated, that is to say, when the operation angle of the expression pedal is minimum, and contrary to the foregoing, the volume of organ sounds based on the signal e is larger than that of rhythm sounds by about 6 dB when the expression pedal is completely depressed, that is to say, when the operation angle of the expression pedal is maximum. I

It will be appreciated that, in accordance with the present invention, the rhythm signal can be controlled in its level more narrowly than the organ signal irrespective of operation of the common expression pedal.

Although the description has been made with reference to an embodiment having an organ section and a rhythm section,

it will be tialpparent to those skilled in the art that the invention can be u wed in other ways. For example, the one of the different music part playing sections may include an upper manual and a lower manual, while the other includes a pedal keyboard. Still further variations can also be applicable to the inventive concept.

What is claimed is:

1. An electronic musical instrument comprising at least two difierent music part playing sections, an expression control means for varying the volume of the tone signals from said different playing sections simultaneously and by difierent amounts, an amplifier and a loudspeaker; said expression control means including:

an expression controller;

a first input terminal for receiving a tone signal derived from one of said playing sections;

a second input terminal for receiving a tone signal derived from the other of said playing sections;

an output terminal for delivering a tone signal to said amplifier;

a first variable resistance means connected between said first input terminal and said output terminal and having a resistance which is variable responsive to operation of said expression controller, said tone signal from said one playing section passing through said first variable resistance means to said output terminal;

a second resistor connected between said second input terminal and said output terminal and having a resistance higher than the minimum resistance of said first variable resistance means and lower than the maximum resistance of said first variable resistance means, said tone signal from said other playing section passing through said second resistor to said output terminal; and

a third resistor connected between said first and second input terminals and having a resistance approximately the same as the output impedance of said playing sections.

2. The electronic musical instrument according to claim 1, wherein said at least two different music part playing sections comprise an organ section and a rhythm section.

3. The electronic musical instrument according to claim 1, wherein said first variable resistance means includes a light sensitive variable resistor.

4. The electronic musical instrument according to claim 1 wherein said first resistance means includes a variable resistor whose value varies in accordance with amount of light irradiated thereto, said expression controller includes a manually operated expression pedal, and said expression control means further includes a light source for irradiating light to said light variable resistor, and a shutter means disposed between said light source and said light variable resistor and arranged to move with said expression pedal, said shutter means having an opening for controlling amount of light from said light source to said light variable resistor in accordance with operation of said expression pedal.

5. The electronic musical instrument according to claim 4 wherein said shutter means comprises a plate having a tapered opening therein disposed between said light source and said light variable resistor, the portion of said tapered opening through which said light source communicates with said light variable resistor varying in accordance with operation of said expression pedal, thereby varying the resistance of said light variable resistor. 

1. An electronic musical instrument comprising at least two different music part playing sections, an expression control means for varying the volume of the tone signals from said different playing sections simultaneously and by different amounts, an amplifier and a loudspeaker; said expression control means including: an expression controller; a first input terminal for receiving a tone signal derived from one of said playing sections; a second input terminal for receiving a tone signal derived from the other of said playing sections; an output terminal for delivering a tone signal to said amplifier; a first variable resistance means connected between said first input terminal and said output terminal and having a resistance which is variable responsive to operation of said expression controller, said tone signal from said one playing section passing through said first variable resistance means to said output terminal; a second resistor connected between said second input terminal anD said output terminal and having a resistance higher than the minimum resistance of said first variable resistance means and lower than the maximum resistance of said first variable resistance means, said tone signal from said other playing section passing through said second resistor to said output terminal; and a third resistor connected between said first and second input terminals and having a resistance approximately the same as the output impedance of said playing sections.
 2. The electronic musical instrument according to claim 1, wherein said at least two different music part playing sections comprise an organ section and a rhythm section.
 3. The electronic musical instrument according to claim 1, wherein said first variable resistance means includes a light sensitive variable resistor.
 4. The electronic musical instrument according to claim 1 wherein said first resistance means includes a variable resistor whose value varies in accordance with amount of light irradiated thereto, said expression controller includes a manually operated expression pedal, and said expression control means further includes a light source for irradiating light to said light variable resistor, and a shutter means disposed between said light source and said light variable resistor and arranged to move with said expression pedal, said shutter means having an opening for controlling amount of light from said light source to said light variable resistor in accordance with operation of said expression pedal.
 5. The electronic musical instrument according to claim 4 wherein said shutter means comprises a plate having a tapered opening therein disposed between said light source and said light variable resistor, the portion of said tapered opening through which said light source communicates with said light variable resistor varying in accordance with operation of said expression pedal, thereby varying the resistance of said light variable resistor. 